Paper feeding device

ABSTRACT

According to one embodiment, a paper feeding apparatus arranged along the left-right direction on one side of an image forming apparatus and configured to feed stacked sheets one by one in order from a top sheet to the image forming apparatus from a paper feeding side adjacent to the image forming apparatus includes: a base plate; a tray on which plural sheets are stacked; a front-side guide member; a rear-side guide member; a paper-feeding-side guide member; an opened section formed by opening one side opposite to the paper-feeding-side guide member; and an auxiliary front guide member configured to regulate a position on the front end side of the sheets. The auxiliary front guide member has a sheet guiding section configured to come into contact with a corner on the front side of the sheets placed deviating from a proper placing state and guide the corner to the auxiliary guide section.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from: U.S. provisional application 61/351,738, filed on Jun. 4, 2010; the entire contents of each of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to the structure of guide members configured to guide, in a predetermined direction, sheets to be loaded.

BACKGROUND

There is proposed a paper feeding apparatus externally attached to an image forming apparatus such as an MFP (Multi Function Peripheral). This paper feeding apparatus is attached to the outer side on one side of the image forming apparatus. Several thousand sheets for printing are stacked on a tray for stacking sheets. Therefore, the paper feeding apparatus is also called LCF (LARGE-CAPACITY-FEEDER). The tray moves up as the number of stacked sheets decreases. The sheets stacked on the tray are picked up by a pickup roller one by one in order from the one sheet at the top position, delivered to a separating and conveying roller pair configured to, for example, prevent double feed, and fed to a sheet conveying system in the MFP.

In the LCF, a sheet stacking section in which the tray is arranged to be capable of moving up and down is attached in a housing-like exterior member to be capable of being drawn out. When the sheet stacking section is drawn out to the front side in a state in which the LCF is arranged side by side with the MFP, the tray appears.

When sheets stored in the sheet stacking section are exhausted, in order to supply sheets, a user draws out the sheet stacking section to the front side, holds sheet bundles each including, for example, about five hundred sheets with both hands, and sequentially stacks up the sheet bundles on the tray.

In order to align and hold several thousand sheets to be stacked, guide members configured to guide three sides of the sheets are provided in the up-down direction in the sheet stacking section. The remaining one side on the opposite side of a sheet feeding side is widely opened. The sheet bundle of five hundred sheets is heavy. The hands of the user holding the sheet bundle interfere with the guide members. Therefore, work for aligning the sheet bundle in a proper direction and placing the sheet bundle on the tray takes time. In some cases, the stacking work for the sheets ends with the sheets set in an improper direction.

If the direction of the sheets is improper in this way, this causes a skew when a sheet is conveyed to the image forming apparatus. In some cases, a jam is caused. Therefore, it is desired that a sheet bundle can be surely stacked on a tray in a proper direction by simple work.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall diagram of an MFP attached with an LCF according to an embodiment;

FIG. 2 is a perspective view of a state in which a sheet stacking section of the LCF shown in FIG. 1 is drawn out to the front, wherein a tray is in a lower position;

FIG. 3 is a diagram of the upward movement of the tray, wherein the tray is in an upper position;

FIG. 4 is a perspective view of the sheet stacking section of the LCF shown in FIG. 1;

FIG. 5 is an A arrow view of FIG. 4;

FIG. 6 is a B arrow view of FIG. 4;

FIG. 7 is a top view of a state in which a sheet bundle is loaded on the sheet stacking section in a proper position; and

FIG. 8 is a top view of a state in which the sheet bundle is provisionally loaded on the sheet stacking section.

DETAILED DESCRIPTION

In general, according to one embodiment, a paper feeding apparatus is a paper feeding apparatus arranged along the left-right direction on one side of an image forming apparatus and configured to feed stacked sheets one by one in order from a top sheet to the image forming apparatus from a paper feeding side adjacent to the image forming apparatus. The paper feeding apparatus includes: a base plate; a tray on which plural sheets are stacked, the tray being capable of moving up and down with respect to the base plate; a front-side guide member arranged on the front side in the front-rear direction orthogonal to a paper feeding direction from the paper feeding side to the image forming apparatus, attached to the front end of the base plate, and extending upward; a rear-side guide member arranged on the rear side in the front-rear direction orthogonal to the paper feeding direction, attached to the rear end of the base plate, and extending upward; a paper-feeding-side guide member forming an aligning member on the paper feeding side for the stacked sheets, attached to the base plate, and extending upward; an opened section formed by opening one side opposite to the paper-feeding-side guide member; and an auxiliary front guide member arranged between the front-side guide member and the paper-feeding-side guide member and configured to regulate, with an auxiliary guide section, a position on a front end side of the sheets stacked on the tray, the auxiliary front guide member having a sheet guiding section configured to come into contact with a corner on a front side of the paper feeding side of the sheets placed deviating from a proper placing state, and configured to guide the corner to the auxiliary guide section with external force in the paper feeding direction applied to the sheets.

A paper feeding apparatus according to an embodiment is explained in detail below with reference to the accompanying drawings.

FIG. 1 is an overall diagram of an MFP attached with an LCF, which is the paper feeding apparatus according to this embodiment. FIG. 2 is a perspective view of a state in which a sheet stacking section of the LCF shown in FIG. 1 is drawn out to the front side, wherein a tray is in a lower position. FIG. 3 is a diagram of the upward movement of the tray, wherein the tray is stopped in the top position. The figure does not indicate that, when the sheet stacking section is drawn out to the front, the tray automatically moves up. FIG. 4 is a perspective view of the sheet stacking section of the LCF shown in FIG. 1. FIG. 5 is an A arrow view of FIG. 4. FIG. 6 is a B arrow view of FIG. 4.

In FIG. 1, in an MFP 100, which is an example of an image forming apparatus including a printer function and a copy function, paper feeding cassettes 102 configured to store sheets are arranged in plural stages in a paper feeding cassette section 101 in a lower part. The paper feeding cassettes 102 can be drawn out to the front side indicated by an arrow F. A printer section 103 is arranged on the paper feeding cassette section 101. The sheets stored in the paper feeding cassettes 102 are fed to the printer section 103 by a sheet conveying section 104 in which a sheet conveying path extends in the up-down direction. The sheets having images printed thereon by the printer section 103 are discharged to a paper discharge tray 105 at the upper end. The sheet conveying section 104 is arranged on one side, i.e., the right side of the MFP 100.

In an LCF 1, a sheet stacking section 10, on which sheets are stacked, is attached to be capable of being housed in an exterior case section 50 via a slide rail 51. The LCF 1 feeds, in a state in which the sheet stacking section 10 is housed in the exterior case section 50, sheets one by one from a paper feeding section 60 provided in an upper part of the left side wall surface of the exterior case section 50 to the sheet conveying section 104 of the MFP 100. The sheet stacking section 10 changes, according to plural paper sizes such as an A4 size, an A5 size, and a Letter size, attaching positions of guide members configured to regulate front-rear direction positions of the sheets.

The LCF 1 is supported by supporting plates 106 extending in an arrow R direction from the lower end of the MFP 100. The LCF 1 performs paper feeding to the MFP 100 in a state in which the LCF 1 is fixed to the right side of the MFP 100. When unlocking is performed by a lock lever 53, the LCF 1 and the supporting plates 106 are unlocked. The supporting plates 106 can slide in the arrow R direction.

As shown in FIGS. 2 and 3, when the sheet stacking section 10 is drawn out to the front side indicated by the arrow F, a tray 11, on which sheets are stacked, is driven by, for example, an elevating mechanism M of a belt driving type and moves down to the bottom position to enable stacking of sheets. The number of sheets stacked on the sheet stacking section 10 is not specifically limited. For example, about three thousand to four thousand sheets are stacked. In the elevating mechanism M, an endless belt 31 is suspended between pulleys 30 arranged to be vertically opposed to each other. The elevating mechanism M motor-drives one pulley 30 to thereby lift and lower the tray 11 connected to the endless belt 31. The elevating mechanism M is not limited to this configuration. The elevating mechanism M may have any configuration as long as the elevating mechanism M can lift and lower the tray 11.

In the sheet stacking section 10 of the LCF 1, slide sections 52 of the slide rail 51 are attached on both the left and right sides of a base plate 12 having a rectangular flat plate shape located at the bottom. The long sides of the base plate 12 are left and right sides and the short sides of the base plate 12 are front and rear sides. A front cover 13 is attached to the front end of the base plate 12. On the left side of the sheet stacking section 10, a left side wall section 14 is attached to the left side of the base plate 12. The upper end of the left side wall section 14 is set lower than an upper plate 54 of the exterior case 50 to make it possible to deliver a top sheet placed on the tray 11 to a separating and conveying roller pair 61 of the paper feeding section 60 through a gap between the upper end and the upper plate 54.

In the paper feeding section 60 shown in FIG. 4, pickup rollers 62 are arranged in the exterior case 50 to correspond to the top sheet. The paper feeding section 60 delivers sheets in an arrow G direction one by one in order from the top sheet. The paper feeding section 60 prevents double feed with the separating and conveying roller pair 61 to feed one sheet to the MFP 100.

The inner side of the left sidewall section 14 is formed by a left side plate 16, which is a paper feeding side guide member. The left side plate 16 has a function of performing alignment in the left direction of a sheet bundle 2 stacked on the tray 11. Plural side guide sections 17 a, 17 b, 17 c, and 17 d are formed spaced apart from one another along a longitudinal direction of the left side plate 16 to face inward. The side guide sections 17 a, 17 b, 17 c, and 17 d come into contact with the left side surface of the sheet bundle 2 stacked on the tray 11 and perform alignment in the left direction of the sheet bundle 2.

At the front end of the base plate 12, a front-side guide plate 18, which is a guide member, is attached along the up-down direction further on the inner side than the front cover 13 and in the center in the left-right direction. At the rear end of the base plate 12, a rear-side guide plate 19, which is a guide member, is attached along the up-down direction to be opposed to the front-side guide plate 18. The front-side guide plate 18 and the rear-side guide plate 19 perform alignment in the front-rear direction of the sheet bundle 2 stacked on the tray 11.

Attaching positions of the front-side guide plate 18 and the rear-side guide plate 19 with respect to the base plate 12 can be changed in the front-rear direction according to a sheet size of the sheet bundle 2 stacked on the tray 11 or the direction of sheets to be stacked. First through-holes 20 a and second through-holes 20 b, through which the front-side guide plate 18 and the rear-side guide plate 19 are pierced, are formed in the tray 11. Therefore, the front-side guide plate 18 and the rear-side guide plate 19 do not obstruct the upward and downward movement of the tray 11.

When the sheet bundle 2 is placed on the tray 11 of the sheet stacking section 10, the left side surface of the sheet bundle 2 comes into contact with the side guide sections 17 a, 17 b, 17 c, and 17 d of the left side guide plate 16 according to the size of sheets, whereby alignment in the left direction is performed. The front and rear surfaces of the sheet bundle 2 come into contact with the front-side guide plate 18 and the rear-side guide plate 19, whereby alignment in the front-rear direction is performed. Since the sheets have errors with respect to standardized sizes, hole positions of attaching screws can be adjusted or screw holes through which the attaching screws pierce are formed as long holes such that adjustment of attaching positions of the front-side guide plate 18 and the rear-side guide plate 19 can be performed.

If an opened section 22 is provided on the left side of the sheet stacking section 10, an operator can easily load sheets by inserting sheet-gripping hands into the opened section 22. Specifically, if the operator grips, for example, by both hands, the right side of a sheet bundle that the operator can hold in one loading work (hereinafter referred to as small amount sheet bundle) S, inserts the hands into the opened section 22 on the right side, and lowers the hands from right above the tray 11, the small amount sheet bundle S can be placed on a saucer 11.

If there is no wall section on a right side 21 of the sheet stacking section 10, position regulation in the right direction of the sheet bundle 2 stacked on the tray 11 cannot be performed. The sheet bundle 2 shifts in the right direction because of the influence of vibration or the like. Therefore, an end guide plate 23 having length not obstructing the loading of the small amount sheet bundle S is attached on the right side and the rear of the base plate 12.

As shown in FIG. 8, to load the small amount sheet bundle S in the sheet stacking section 10, the small amount sheet bundle S is slightly turned in the counterclockwise direction and lowered horizontally rather than being directly lowered from right above the tray 11.

Corners on the left and right on the front side of the small amount sheet bundle S are represented as 2A and 2B and corners on the left and right on the rear side of the small amount sheet bundle S are represented as 2C and 2D. The front side right corner 2B of the small amount sheet bundle S is turned in the counterclockwise direction to protrude from the opened section 22.

A part of the short side on the front side of the small amount sheet bundle S is partially brought into contact with the front-side guide plate 18 and a part of the short side on the rear side of the small amount sheet bundle S is partially brought into contact with the rear-side guide plate 19. A sheet side near the rear side left corner 2C of the small amount sheet bundle S is brought into contact with the left side plate 16. This makes it possible to stably horizontally hold the small amount sheet bundle S in the tilted state explained above and smoothly lower the small amount sheet bundle S.

Because of the presence of the opened section 22, the operator can perform such loading work for the small amount sheet bundle S while keeping on gripping the right side portion of the small amount sheet bundle S with the right hand. A state in which the small amount sheet bundle S is loaded shown in FIG. 8 is a provisional loaded state that is not considered to be a proper loaded state because the entire left side surface of the small amount sheet bundle S does not come into contact with the left side guide plate 16.

In this provisional loaded state, if the right side surface on the front side of the small amount sheet bundle S is pushed into the left side, the entire small amount sheet bundle S turns in the clockwise direction and the entire left side surface of the small amount sheet bundle S comes into contact with the left side guide plate 16.

Therefore, in this embodiment, an auxiliary front guide member 24 configured to assist the turn in the clockwise direction of the small amount sheet bundle S in the provisional loaded state and align the front side of the small amount sheet bundle S is attached to the left side guide plate 16 along the up-down direction.

As shown in FIGS. 5 and 6, the auxiliary front guide member 24 extends from the base plate 12 to the upper end of the left side guide plate 16 and is attached to the left side guide plate 16 by not-shown screws. Screw holes 25 through which the screws are inserted are formed in plural places according to the size of sheets.

The auxiliary front guide member 24 includes an auxiliary guide section 24A in which a sheet contact surface extending from the left side guide plate 16 to the front-side guide plate 18 is formed as a flat surface and a sheet guiding section 24B formed at the distal end of the auxiliary guide section 24A. The sheet contact surface of the auxiliary guide section 24A and a sheet contact surface of the front-side guide plate 18 are aligned in a pre-alignment position that is a proper placing position for sheets.

If the small amount sheet bundle S shown in FIG. 8 is in the provisional loaded state, the distal end of the front side left corner 2A of the small amount sheet bundle S further projects to the front side than the pre-alignment position. Therefore, the sheet guiding section 24B is formed as a slope having an angle θ that comes into contact with the distal end of the front side left corner 2A of the small amount sheet bundle S that projects further to the front side than the pre-alignment position.

The sheet guiding section 24B tilts to the front side from the distal end of the auxiliary guide section 24A. Therefore, when the left side surface of the small amount sheet bundle S is pushed by a hand from the opened section 22, the front side left corner 2A of the small amount sheet bundle S is guided to the auxiliary guide section 24A while coming into contact with the contact surface of the sheet guiding section 24B. When the front side left corner 2A of the small amount sheet bundle S is guided by the auxiliary guide section 24A, the entire small amount sheet bundle S turns in the clockwise direction. When the front side left corner 2A of the small amount sheet bundle S reaches the auxiliary guide section 24A, the turn in the clockwise direction of the small amount sheet bundle S is stopped.

When the right side surface of the small amount sheet bundle S continues to be pushed by the hand from the opened section 22, the front side surface of the small amount sheet bundle S is guided by the auxiliary guide section 24A and the front-side guide plate 18. The rear side surface of the small amount sheet bundle S is guided by the rear-side guide plate 19 and moves to the left side guide plate 16. As a result, the left side surface of the small amount sheet bundle S comes into contact with the side guide sections 17 a, 17 b, 17 c, and 17 d of the left side guide plate 16. The small amount sheet bundle S is aligned in a proper position.

In this embodiment, a maximum tilt angle θ of the sheet guiding section 24B is set to 45 degrees and minimum length of the sheet guiding section 24B is set to 2 mm. The shape of the sheet guiding section 24B does not have to be the shape of a tilted member unlike this embodiment as long as the sheet guiding section 24B comes into contact with the front side left corner 2A of the small amount sheet bundle S and guides the front side left corner 2A to the auxiliary guide section 24A. For example, the shape of the sheet guiding section 24B may be a curved shape (a concave surface or a convex surface).

In this embodiment, the size of the sheet bundle 2 is, for example, the A4 size. In this case, the front-side guide plate 18 and the rear-side guide plate 19 pierce through the first through-holes 20 a formed in positions close to the front and rear ends of the tray 11. In order to guarantee the up and down actions of the tray 11, a first cutout section 26 is formed in a portion that interferes with the auxiliary front guide member 24 attached to a sheet position of the A4 size. The first through-holes 20 a are formed rather large in the front-rear direction to correspond to attaching positions of the front-side guide plate 18 and the rear-side guide plate 19 in the A4 size and the Letter size. Similarly, the first cutout section 26 is formed rather long in the front-rear direction to correspond to the attaching positions of the auxiliary front guide member 24 in the sheets of the A4 size and the Letter size.

The second through-holes 20 b are formed to correspond to the front-side guide plate 18 and the rear side plate 19 attached, for example, in a sheet position of the A5 size. A second cutout section 27 is formed to correspond to an attaching position of the auxiliary front guide member 24 in the sheet of the A5 size.

According to this embodiment, the sheet stacking section 10 is configured to store sheets having different sizes. Therefore, the front-side guide plate 18 and the rear-side guide plate 19 are inserted through the first through-holes 20 a and the second through-holes 20 b formed in the tray 11 to enable the tray 11 to move up and down. Therefore, the width of the front-side guide plate 18 and the rear-side guide plate 19 for regulating the front and the rear of the sheet bundle 2 is smaller than the length in the left-right direction of the sheet bundle 2. The small amount sheet bundle S is unstably loaded in the sheet stacking section 10.

However, the auxiliary front guide member 24 is attached in the left-right direction side by side with the front-side guide plate 18. Therefore, when, for final loading, the small amount sheet bundle S in the provisional loaded state is pushed from the opened section 22 side, the front side left corner 2A of the small amount sheet bundle S is guided to the auxiliary guide section 24A while coming into contact with the sheet guiding section 24B. The left front end face of the small amount sheet bundle S is guided to the auxiliary guide section 24A. The small amount sheet bundle S is stacked in a proper state. Even if the small amount sheet bundle S is insufficiently pushed in to change the small amount sheet bundle S from the provisional loaded state to a final loaded state, when sheets are picked up one by one in order from a top sheet and fed to the MFP 100, contact resistance between the front side left corner 2A of the sheets and the sheet guiding section 24B of the slope is small. Therefore, the sheets are smoothly fed and conveyance failures such as a jam are reduced.

The present invention can be carried out in other various forms without departing from the spirit or the main characteristics of the present invention. Therefore, the embodiment is merely an example in every aspect and should not be limitedly interpreted. The scope of the present invention is indicated by the scope of the claims and is by no means limited by the text of the specification. Further, all modifications and various improvements, substitutions, and alterations belonging to the scope of equivalents of the claims are within the scope of the present invention. 

1. A paper feeding apparatus arranged along a left-right direction on one side of an image forming apparatus and configured to feed stacked sheets one by one in order from a top sheet to the image forming apparatus from a paper feeding side adjacent to the image forming apparatus, the paper feeding apparatus comprising: a base plate; a tray on which plural sheets are stacked, the tray being capable of moving up and down with respect to the base plate; a front-side guide member arranged on a front side in a front-rear direction orthogonal to a paper feeding direction from the paper feeding side to the image forming apparatus, attached to a front end of the base plate, and extending upward; a rear-side guide member arranged on a rear side in the front-rear direction orthogonal to the paper feeding direction, attached to a rear end of the base plate, and extending upward; a paper-feeding-side guide member forming an aligning member on the paper feeding side for the stacked sheets, attached to the base plate, and extending upward; an opened section formed by opening one side opposite to the paper-feeding-side guide member; and an auxiliary front guide member arranged between the front-side guide member and the paper-feeding-side guide member and configured to regulate, with an auxiliary guide section, a position on a front end side of the sheets stacked on the tray, the auxiliary front guide member having a sheet guiding section configured to come into contact with a corner on a front side of the paper feeding side of the sheets placed deviating from a proper placing state, and configured to guide the corner to the auxiliary guide section with external force in the paper feeding direction applied to the sheets.
 2. The apparatus according to claim 1, wherein the sheet guiding section of the auxiliary front guide member is a tilting section that tilts from a distal end of the auxiliary guide section to the front side.
 3. The apparatus according to claim 2, wherein a maximum tilt angle of the sheet guiding section is 45 degrees and minimum length of the sheet guiding section is 2 mm.
 4. The apparatus according to claim 1, wherein the auxiliary front guide member is supported from the paper-feeding-side guide member to the front-side guide member.
 5. The apparatus according to claim 1, wherein attaching positions in the front-rear direction of the front-side guide member and the auxiliary front guide member are changed according to a size of the stacked sheets.
 6. The apparatus according to claim 1, wherein a cutout section that does not interfere with the auxiliary front guide member is provided in the tray to correspond to an attaching position of the auxiliary front guide member. 